The two preschoolers were holding hands Thursday when they were mowed down in Chinatown by a runaway 9,400-pound delivery van as they returned to their day care center after a visit to the library.

In death, the huge line of mourners reached from one funeral home to the other like outstretched arms as hundreds turned out to say farewell - and to embrace the shaken families.

"It's very difficult when it's a child," said Gil Medina, an FDNY peer counselor.

Hayley, wearing a purple dress, was surrounded by a sea of pink and yellow flowers at a wake at Ng Fook Funeral Home. At nearby Wah Wing Sang Funeral Home, Diego's mother, Wana Wu, cried by the side of the painfully small white coffin that held her baby.

Martinez - an emergency medical technician who patrols the Chinatown area - sobbed and clutched another one of his son's toys, a stuffed blue monkey.

Martinez was off duty the day of the accident, but might have responded to the accident if he'd been on duty.

"I couldn't even imagine," Phelan said. "My heart goes out to them."

The van driver had stepped out of the vehicle with the engine running, unaware it was in reverse. He was not charged.

"It is so sad and painful for a parent to bury a child," said Rufina Camilo, whose son Jonathan played with Diego.

Mourners said it was difficult to say goodbye just a day before Monday's celebration of the Chinese New Year, but that the families are pulling together.

"Everybody's so distraught, such a young baby," said Charles Cordero, a friend of Diego's mom.

Diego was buried in Kensico Cemetery in Valhalla, Westchester County. Mourners held white roses and bowed before the grave, leaving behind burning incense. Hayley was buried quickly and with little ceremony at Mount Pleasant Cemetery, just a short ride away.

The Aunt of Hayley Ng actually works in my company. She's asking everyone for their help in making the Manhattan District Attorney investigate this case further. Please sign this petition, it only takes 1 minute to sign. Remember you don't want this to happen to anyone you know.